S. J. K. expresses her appreciation to the National Institute for International Education of Korea (NIIED) and the Research School of Ruhr-University Bochum (RUB-RS) for providing financial support. The authors thank the Materials Research Department of RUB for supporting this work. R.B. and M.B. are thankful for financial support by the MIWFT-NRW.
Intrinsic Nitrogen-doped CVD-grown TiO2 Thin Films from All-N-coordinated Ti Precursors for Photoelectrochemical Applications†
Article first published online: 1 MAR 2013
Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chemical Vapor Deposition
Volume 19, Issue 1-3, pages 45–52, March 2013
How to Cite
Kim, S. J., Xu, K., Parala, H., Beranek, R., Bledowski, M., Sliozberg, K., Becker, H.-W., Rogalla, D., Barreca, D., Maccato, C., Sada, C., Schuhmann, W., Fischer, R. A. and Devi, A. (2013), Intrinsic Nitrogen-doped CVD-grown TiO2 Thin Films from All-N-coordinated Ti Precursors for Photoelectrochemical Applications. Chem. Vap. Deposition, 19: 45–52. doi: 10.1002/cvde.201206996
- Issue published online: 11 MAR 2013
- Article first published online: 1 MAR 2013
- Manuscript Revised: 11 JUL 2012
- Manuscript Received: 24 APR 2012
- N-coordinated Ti precursor;
- TiO2 thin films
N-doped titanium dioxide (TiO2) thin films are grown on Si(100) and indium tin oxide (ITO)-coated borosilicate glass substrates by metal-organic (MO)CVD. The intrinsic doping of TiO2 thin films is achieved using all-nitrogen-coordinated Ti precursors in the presence of oxygen. The titanium amide-guanidinate complex, [Ti(NMe2)3(guan)] (guan = N,N′-diisopropyl-2-dimethylamidoguanidinato) has been developed to compensate for the thermal instability of the parent alkylamide [Ti(NMe2)4]. Both of these amide-based compounds are tested and compared as precursors for intrinsically N-doped TiO2 at various deposition temperatures in the absence of additional N sources. The structure and morphology of TiO2 thin films are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Rutherford back scattering (RBS), nuclear reaction analysis (NRA), and secondary ion mass spectrometry (SIMS) analyses are performed to determine N content and distribution in the films. The optical and photoelectrochemical properties of TiO2 thin films on ITO substrates are also examined. N-doped TiO2 thin films, grown from [Ti(NMe2)3(guan)] at 600 °C, exhibit the lowest optical absorption edge (3.0 eV) and the highest visible light photocurrent response. When compared to undoped TiO2, while in UV light photoconversion efficiency decreases significantly, the intrinsically N-doped TiO2 shows enhanced photocurrents under visible light irradiation.